The invention relates generally to a method of and apparatus for the loading and use of turntables in the rendition of taped programs, and more particularly in the loading and use of a single turntable on which the tape of a taped program is wound on in controlled lengths per revolution of the turntable near the periphery of the turntable and off near the center of the turntable simultaneously.
Heretofore, the tape of a taped program of the length of a movie, television show, or musical show, has been loaded on a turntable by winding it from the center outward, thereby varying the length of tape per revolution of the turntable directly with the radius of the winding. The outer end of the tape is led through an associated apparatus for the rendition of the taped program, and out to be rewound from the center outward on a second turntable. When the program ends, it can be replayed from the second turntable back onto the first turntable. The two turntables are required because they must turn at varying speeds to deliver and take up tape at a constant linear rate from turntable windings of varying radii.
Also, in the prior art where one turntable has been employed, winding tape from the center of a reel through a cooperating apparatus for the rendition of the taped program and peripherally rewinding it back on the same reel has necessarily been confined to very short lengths of tape loosely wound to allow for slippage and friction between windings due to the reel turning several times to deliver from the center the same lengths of tape that are peripherally taken up in less than one revolution.
A substantially improved method and apparatus for the loading and use of a single turntable in the rendition of taped programs is disclosed in U.S. Pat. No. 4,066,221 and the continuation application of the application of this patent, Ser. No. 844,471, filed Oct. 21, 1977, and the continuation-in-part application Ser. No. 844,469, filed Oct. 21, 1977. In the method and apparatus of this patent and applications, the tape is wound on edge on top of the single turntable and is held in place against the table by equally spaced pressure pads that extend radially to restrict circumferential movement of the tape across the respective radius, while permitting movement along the radius. In applying this basic concept, it was contemplated that equal lengths of tape for each revolution of the turntable would be wound onto the turntable. However, it has been found that where a plurality of tapes have been spliced together to make up a selected program, the characteristics of the individual tapes, such as thickness and stretchiness, may preclude the use of this concept of equal lengths for every revolution of the turntable throughout the entire program.
Additionally, where many hours of film are stored on a table and the film is continuously removed from the inner loop and wound on at the outer loop, forces such, for example, as are caused by the spring forces of the film on the table, may build up and cause a change in the circumference of the tape on the table. Such forces may make it impossible to hold the desired outer circumference of film. Furthermore, these forces may have an adverse effect on the desired symmetry of the scallops formed in the inner loops of the stored tape between adjacent radii.